1. Field of the Invention
The invention relates to a novel process for the preparation of formylimidazoles of the general formula: ##STR4## or its tautomers, in which R.sup.1 is hydrogen or alkyl, and R.sup.2 is hydrogen, halogen or alkyl.
2. Background Art
Formylimidazoles are important intermediates for the preparation of pharmaceutical active ingredients, such as, for diuretics or antihypertensives (WO 92/20651).
A process for the preparation of formylimidazoles is described, for example, in Swiss Patent No. 685,496. In this process, hydroxymethylimidazoles are oxidized by catalytic oxidation in the presence of noble-metal catalysts, such as, platinum-bismuth, platinum black, platinum or palladium on activated carbon, while passing in oxygen to give the formylimidazoles. Disadvantages of such process are long reaction times and the formation of by-products.